PHYTOCHEMICAL STUDY AND ANTIBACTERIAL ACTIVITY OF GLYCYRRHIZA GLABRA L. AND ITS COMBINATION WITH GENTAMICIN AGAINST KLEBSIELLA PNEUMONIAE, IN VITRO

Background and Aim:Klebsiella pneumoniae is one of those bacteria that its multidrug resistance has increased its mortality. One solution is finding natural bioactives that have synergistic interactions with antibiotics. The root of Glycyrrhiza glabra L. (RG) is one of those sources with many therapeutic properties, as result, we aimed to evaluate antibacterial effect of its combination with Gentamicin.Methods:In this experimental study, total phenolic content (TPC) and total flavonoids content (TFC) of hydroalcoholic extract of RG were determined by Folin-Ciocalteu and Aluminum chloride colorimetric method. Minimal inhibitory concentration (MIC) of Gentamicin and RG extract on the standard strain of K. pneumoniae were determined by resazurin-microdilution assay and finally, for detecting an interaction between them we used Checkerboard assay, each test was repeated for three times.Results:TPC and TFC of this extract were measured 57.19 mg equivalent Gallic acid/g dried extract and 40.1 mg equivalent Rutin/g dried extract respectively. MICs for gentamicin (4 µg/ml) and RG (131 mg/ml) were reported by detecting the last wells with the lowest concentration of agents that had no color change from blue to pink. Mean Fractional Inhibitory Concentration (FIC) Index for their combination was 5 which showed great antagonistic effect between RG extract and gentamicin.Conclusion:Results indicated that RG is a good source for phenolic and flavonoid components and although this crude extract contains some antibacterial components, there are some with notable antagonistic interaction with Gentamicin which is wildly used against this bacteria, as result, this drug interaction should be considered in patients infected by this bacteria.

کلیدواژه ها:

Drug Combination ، Glycyrrhiza ، Gentamicin ، Drug Antagonism ، Klebsiella pneumoniae